The present invention relates to an armature for a seat back headrest and in particular to a one piece hollow armature made of molded plastic.
The headrest for a seat assembly, and in particular an automotive vehicle seat assembly, is typically made of an upholstered foam pad surrounding a supporting frame. The frame is in turn carried by one or two support legs that extend downwardly into the seat back of the vehicle seat assembly. Numerous designs have been developed for headrest frames and for attaching the frames to support legs.
In one design for a headrest, the headrest frame is made of a metallic plate and is attached to the support legs by clamps and other hardware. Some of the attachments are rigid without any relative motion. Others are adjustable to vary the inclination of the headrest by rotating the headrest body about a laterally extending horizontal axis usually formed by an upper portion of the headrest support legs. The adjustment is provided by using a clamp or J-strap having a bearing portion surrounding a horizontal journal portion of the support legs. The clamps or straps, are attached at both ends to the headrest frame with the friction between the clamp and support legs holding the headrest in its inclined positions. Several variations of this basic concept have been developed.
To form an attractively shaped headrest pad around a flat plate, more foam is used than needed to provide sufficient adding for a seat occupant. To reduce the amount of foam used, some headrests are designed with a hollow frame with the inclination adjustment mechanism contained inside the hollow body. A more complex adjustment mechanism is typically used in such a case. The hollow headrest frames are generally of two piece construction and are joined together after assembly of the internal adjustment mechanism. Once the hollow frame is assembled, the foam pad is molded around the frame.
A disadvantage of the various headrest configurations is the numerous individual components that are necessary for assembling the frame and for mounting the frame to the support legs, especially when angular adjustability is provided. Specially designed hardware is often to assembly and mount the frame.
The common feature found in most if not all headrest assemblies is the ability to vertically adjust the position of the headrest relative to the seat back. One common means for providing vertical adjustment is contained in the seat back. The structure for attaching the support legs of the headrest to the seat back allows for the support legs to be withdrawn from the seat back or to be inserted further into the seat back to raise or lower the headrest. The support legs are generally equipped with engagement features such as detents to hold the support legs in place in the seat back.
It is an object of the present invention to provide a headrest frame that is mounted to the headrest support post without specially made custom components or hardware for both fixed and adjustable headrests.
It is an advantage of the present invention that the headrest frame is a one piece plastic molding that once molded can be easily assembled around the headrest support post and fastened thereto without separate fasteners.
The headrest frame of the present invention comprises a single piece injection molded plastic armature having a pair of halves. Each half comprises a wall that has an essentially concave inner surface and an essentially convex outer surface with a peripheral edge of each wall. A portion of the peripheral edge of each half is linear, and along this linear portion the two halves are joined together by a flexible plastic web. The web serves as a hinge when the two halves of the armature are folded together. The peripheries of the two halves are symmetrical about the axis of the hinge so that when the two halves of the armature are folded together, the result is an essentially continuous solid surface.
The armature is closed by rotating the two halves about the flexible web until the peripheral edges of the two halves engage one another forming a closed hollow body, the exterior of which is formed by the outer convex surfaces of the two half portions. Mounting bosses within each half of the armature form bearing surfaces that engage the support legs of the headrest. In one embodiment, the bearing surfaces of the armature halves engage a laterally extending horizontal portion of the headrest support legs to enable rotational adjustment of the headrest angle.
One half of the armature includes posts that extend through apertures in the opposite armature half when closed. After closing, the posts are headed by a heat staking operation forming enlarged heads, like a rivet, to hold the armature closed. A foam pad is molded around the armature utilizing a pour in place process with an upholstery cover applied over the molded foam.
Alternatively, other fasteners can be used, such as bolts, rivets, self tapping screws, etc. Such fasteners are standard, off-the-shelf components that do not need to be custom designed.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying claims.